Home Secretary John Reid has damned his department's immigration operation as "not fit for purpose" with "inadequate" leadership and management systems.

Other failings showed the Home Office could be "dysfunctional" and "wholesale transformation" was "probably" needed.

Although he did not rule out splitting the Home Office, he told MPs there was some logic to its current structure.

The Conservatives said they were not convinced the home secretary could sort the problems out.

Labour ex-minister John Denham meanwhile called Mr Reid's comments "a fairly stark assessment of the state of the Home Office".

Mr Reid told the Commons home affairs committee that jobs could still go after 1,019 foreign prisoners were released without deportation being considered.

But Tory opposite number David Davis said: "It will be alarming for the public to hear that, 10 months after the government were made aware of this problem, there might be a whole new group of foreign criminals on our streets, putting them at risk."

'Stark assessment'

Mr Reid said he had had to deal with "a tidal wave of events" since he became home secretary a fortnight ago.

While his department had been trying to cope with the problems of mass migration, "our system is not fit for purpose", he said.

It's not my job to manage this department - it's my job to lead this department

Asked about the cabinet secretary's suggestion last week that no civil servants were likely to lose their job over the foreign prisoner releases, he said: "Don't count on it."

He said he did not believe the Home Office was "intrinsically dysfunctional... but I do believe from time to time it is dysfunctional in the sense it doesn't work".

He said he wanted to move to a situation where foreign nationals, who had abused the privilege of being in this country by being convicted of a serious offence, "should be deported - full stop".

He said he would not be opposed to publicising the names of the most serious offenders still on the loose if he was asked by the police.

But ex-Tory leader and former Home Secretary Michael Howard said Mr Reid's comments were the "most terrible indictment" of the three men who had been in charge of the Home Office since Labour came to power.

'Years of neglect'

"I believe the Home Office was fit for purpose when I left it in 1997," he told BBC2's Daily Politics.

Mr Reid gave his withering assessment of sections of his department shortly after revealing that 85 of the 186 serious foreign offenders who were released from prison without being considered for deportation since 1999, were still at large.

Of the 37 "most serious" offenders, 27 were in jail, including four murderers, and two were thought to be dead.

During the committee hearing Lin Homer, director general of the Immigration and Nationality Directorate (IND), revealed that 20 of the foreign prisoners were known to have been re-convicted of "more serious" offences after their release.

Six were for sex offences - but not against children - three for violence, 11 for actual bodily harm and grievous bodily harm.

Mr Reid also used the platform to defend his decision to switch Immigration Minister Tony McNulty and Police Minister Liam Byrne, saying their new roles fitted their respective talents.